DESCRIPTION: (Applicant's Abstract) The goal of this project is to characterize changes in central nervous system functioning and cue reactivity associated with success versus failure of two therapies: (1) nicotine patch plus behavior therapy (NP+BT) and (2) placebo patch plus behavioral therapy (PP+BT). Hypothesized relationships derive from neurobiologically based models of addiction, negative affect, and nicotine's situation and trait-dependent effects. Prior, during, and subsequent to NP+BT or PP+BT, individual differences in electrocortical brain activity (background EEG, evoked EEG, and event-related potential) will be assessed during cognitive tasks and in response to smoking and affective cues. Smokers' brain activity will be related to success in maintaining smoking abstinence and post cessation affect. Individual differences in mood, craving, and cognitive performance will be related to these changes in brain activity, success in maintaining abstinence, and smoking-related dimensions of personality and psychopathology. Smokers (N = 300) will be randomly assigned to one of three groups: (1) NP (N = 120), (2) BT (N = 120), or (3) delayed quit (DQ, N = 60). The DQ group will be used to control for effects of repeated exposure (habituation, repeated measures effects) to the experimental assessments/stimuli. Characterization of changes in brain responses to smoking-related and affective cues associated with NP+BT and PP+BT versus the DQ group will help elucidate mechanisms by which NP+BT facilitates success above simple PP+BT in some individuals while failing to do so in others. It is predicted that negative-affect-related personality dimensions and dispositions to neuropsychiatric disorders will differentially predict success with NP+BT versus PP+BT. It is expected that multiple regression and other multivariate techniques will show the use of EEG and ERP measures to be of greater value in predicting treatment success and treatment x individual interactions than heart-rate responses. The long-term objective is to better characterize brain and psychological mechanisms mediating when, in whom, and how NP+BT and BT therapies are effective, so as to develop more effective and individualized smoking interventions.